html * {
  box-sizing: border-box;
  outline: 0;
}

html,
body,
input,
textarea,
button {
  font-family: "Microsoft Yahei", sans-serif;
}

body {
  margin: 0;
}

body,
div,
dl,
dt,
dd,
ul,
ol,
li,
h1,
h2,
h3,
h4,
h5,
h6,
pre,
code,
form,
fieldset,
legend,
input,
textarea,
p,
blockquote,
th,
td,
hr,
button,
article,
aside,
details,
figcaption,
figure,
footer,
header,
hgroup,
menu,
nav,
section {
  margin: 0;
  padding: 0;
}

input,
select,
textarea {
  font-size: 100%;
}

table {
  border-collapse: collapse;
  border-spacing: 0;
}

fieldset,
img {
  border: 0;
}


address,
caption,
cite,
code,
dfn,
em,
th,
var {
  font-style: normal;
  font-weight: 500;
}

ol,
ul {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-size: 100%;
  font-weight: 500;
}

input,
textarea {
  -webkit-appearance: none;
  border-radius: 0;
}

textarea {
  resize: none;
}
@media screen and (max-width: 414px) {
  html {
    font-size: 17.664px;
  }
}

@media screen and (max-width: 375px) {
  html {
    font-size: 16px;
  }
}

@media screen and (max-width: 320px) {
  html {
    font-size: 13.6533px !important;
  }
}
.app {
  width: 100%;
  /*max-width: 750px;*/
  min-height: 100vh;
  margin: auto;
  color: #555;
  background: #f2f2f2;
}
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  height: 4.4rem;
  padding: .5em 1em;
  font-size: 1.2rem;
  background: #ff701a;
  color: #fff;
}
.header-back {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 2rem;
  height: 2rem;
  border: 2px solid #fff;
  border-radius: 50%; 
}
.header-title {
  margin: 0 auto;
  color: #ddd;
}
.header-title-color {
  color: #fff;
}
.header-title-color::after {
  display: inline-block;
  content: '';
  width: 0;
  border-width: .6rem .6rem 0 .6rem;
  border-style: solid;
  border-color: transparent;
  border-top-color: #fff;
}
